The invention discloses a time resolution fluorescent immunochromatographic test strip for detecting metalaxyl, and a preparation method and application thereof. The time resolution fluorescent immunochromatographic test strip comprises a bottom plate and further comprises a sample absorbent pad, a combination releasing pad, a nitrocellulose membrane and a water absorbent pad which are lapped andpasted on the bottom plate in sequence. A metalaxyl monoclonal antibody labelled by fluorescent microspheres is embedded into the combination releasing pad, and a detecting area and a quality controlarea are fixed to the nitrocellulose membrane. A metalaxyl hapten-carrier protein conjugate is sprayed in the detecting area, an anti-sheep and anti-mouse antibody is sprayed in the quality control area, and a metalaxyl hapten is obtained in the modes that N-(2,6-dimethyl phenyl) alanine methyl ester reacts with (4-nitrophenoxy) acetylchloride to generate nitrobenzene metalaxyl, and then the nitrobenzene metalaxyl is subjected to zinc powder reduction. The time resolution fluorescent immunochromatographic test strip and a detecting method provided by the invention have the advantages that operation is easy, sensitivity is high, the detecting speed is high, and the cost is low, and the metalaxyl in large-batch samples can be detected quickly and monitored on site.